Process of making tin-plate.



DANIEL M. SOMERS, OF NEW YORK, N. Y. PROCESS OF MAKING TIN-PLATE.

Specification of Letters Patent.

Patented Oct. 3, 1905.

Application filed June 7,1905. Serial No. 264,090.

To I/ZZ whom it may concern:

Be it known that I, DANIEL M. SOMERS, a citizen of the United States, residing at New York, county ofKings,and State of New York, have invented certain new and useful Improvements in Processes of Making Tin-Plate, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to certain improvements in the process of making tin-plate.

Tin-plate as now commercially manufactured is made by what is known as the lVelsh process. According to this process sheets of black-plate about twenty by twenty eight inches are employed, these sheets where standard or one-hundred-pound plate is being made being about .0116 inch in thickness. These sheets are first subjected to a pickling process to remove the scale therefrom, after which they are annealed. The pickling process leaves the sheets with a rough uneven surface which has to be removed, and this is effected by passing the sheets through several, usually three, stands of cold rolls. In order to effectually smooth the sheets, these rolls necessarily exert a very heavy pressure on the sheets. This pressure hardens them, so that after cold-rolling the sheets become springy and have a certain degree of temper. In order to remove this springiness and temper, the sheets are annealed a second time, after which they are again subjected to a pickling action in a weak acid solution, this being known as white pickling, which removes such scale as may have formed during the annealing process. The sheets are now ready for tinning and are passed into a flux and a tin-bath. They are then dusted and wiped to remove the oil, which, as is well known, adheres to them as a result of the tinning process.

According to the improved process there is employed instead of black-plate what may be termed pickled annealed gray-plate. In an application filed May 24, 1905, Serial No. 262,088, there is disclosed a novel process of producing this plate, said process consisting generally in subjecting sheets of pickled plate to heat and pressure to elongate them,

jafter which they are annealed, these heating,

pressure, and annealing operations being carri d on without permitting the air to come at the plate, so that the formation of scale is prevented, thus making pickling after the heating, pressure, and annealing operations referred to are completed unnecessary. This pickled annealed gray-plate is to be distinguished from the black-plate employed in the W elsh process by reason of the fact that it is free from scale and also by reason of the fact that its surface differs therefrom in that it is smooth and to acertain degree homogeneous. It is also to be distinguished from the plate produced by the lVelsh process by the step of annealing after the black pickling. The step of annealing after black pickling in the Welsh process produces agray annealed plate; but the surface of this plate, as has been pointed out, is rough and uneven, making it necessary to subject the plate in the Welsh process to the heavy cold-rolling pressure referred to, which pressure, while it reduces in a measure the unevennesses, hardens and tempers the plate, making a subsequent annealing necessary and also a subsequent pickling---l (2., the white pickling referred to-to remove the scale formed during the second annealing. The pickled gray-plate to which reference is made in this application has a surface which is slightly frosted in appearance, but is comparatively smooth. In carrying out the improved process this pickled annealed gray-plate is subjected to a light pressure to remove thefrosted appearance, this being conveniently done by subjecting the plate to the step of cold rolling, which cold-rolling surfaces or planishes theplate, removing the very slight roughness which causes the frosted appearance above referred to. The pressure employed in this cold-rolling is very light as compared with the pressure employed in coldrolling in the \Velsh process, and it does not harden the plate and impart to it the springiness and temper which is incident to cold-rolling in the elsh process. The'subsequent annealing therefore which is necessary in the WVelsh process to remove this hardness and temper is rendered unnecessary, and, further, the subsequent pickling to remove the scale due to the annealing in the WVelsh process is also unnecessary. i

In accordance with the improved process after the plate has been subjected to this light cold-rolling it is cleaned in any suitable manner-as, for instance, by subjecting it to a bath of a weak solution of acid. The sheets are then ready for the tinning, Which may be carried out in any usual manner.

I/Vhero the process is to be carried on in what is regarded as the best way, sheets will be employed which are about fifteen feetlong by twenty-eight inches wide,these sheets Where one-hundred-pound standard plate is used being about .0116 inch in thickness. These long sheets, which may be produced according to the process described in the application above identilied and which process may be convenientl y carried out by an apparatus like that disclosed in an application filed iilarch 28,190&, Serial No. 199,831, lend themselves very readily to the manipulation necessary to carry on the process with great economy of labor. The annealing after cold-rolling being unnecessary, the surfacing-rolls may be caused to deliver directly to the cleaning-bath, and the sheets may emerge from this bath directly into the tinning-bath. The process may therefore be -arrie l on as a continuous process. the sheets passing directly from one apparatus to the next without the necessity of any intermediate handling, which of course n'iaterially reduces the cost of production. After the sheets emerge from the tinning-bath they may be cut into commercial sizes by any desired cutting or shearing armaratus.

\Vhat is claimed is 1. The process of making tin-plate which consists in subjecting pickled annealed grayplate to light pressure to surface it, subsequently cleaning the plate and then tinning it) 2. The process of making tin-plate which consists in subjecting long sheets of pickled annealed gray-plate to light rolling pressure to surface the plate, causing the plate to be passed directly from the rolls into a cleaningbath and then passing the plate directly from the cleaning-bath into the tinning-bath.

3. The process of making tin-plate which consists in subjecting long sheets of pickled annealed gray-plate to light rolling pressure to surface the plate, causing the plate to be passed directly from the rolls into a cleaningbath and then passing the plate directly from the cleaning-bath into the tinning-bath, and then cutting the sheets into short lengths.

In testimony whereof I have hereunto set my hand in the presence of two subscribing Witnesses.

DANIEL M. SOMERS.

Nitnesses:

A. WHITE, G. GALIANI. 

